1. Field of the Invention
The present invention generally relates to an apparatus for testing electrical sockets with a test probe, and more specifically, to systems for aligning the test probe for insertion into the socket.
2. Background Information
Electrical sockets, such as those used for the insertion of semi-conductor chips, are tested during the manufacturing process to verify their functioning and connection properties. The sockets are tested by the insertion of a test probe which has a head which is shaped approximately in the same dimensions as the semi-conductor chip which will go in that socket. Electrodes are arranged along the sides of the test probe head in the same spacing and configuration as the electrodes of the semi-conductor chip. By contacting the electrodes of the socket, the electrodes of the test probe head can make electrical contact and allow tests to be run on the socket.
The semi-conductor sockets are typically arranged on a printed circuit board (PCB) and are tested by placing the board on an X-Y test bed. The testing system with a test probe head attached moves to align with each socket to be tested. When the socket is in position, the test probe head is lowered toward the socket, and pressed into place in the socket.
A problem is that the sockets on a PCB are not always accurately positioned. They may be rotated from alignment with the X and Y axis of the PCB, displaced along the X or Y axis, or both, or they may be tilted from the plane of the PCB. Since the tolerances between the socket and the semi-conductor chip, and therefore the test probe head, are very small, these small discrepancies in position can be a problem. Pressing the test probe head into a misaligned socket can damage the terminals in the socket, can cause excessive wear on the test probe head, and can lead to shortened life of both, as well as inaccurate test results.
Various systems have been utilized to compensate for this discrepancy in position of the socket. These include the use of a suction cup for attachment between the socket and the test probe head, a camera guided alignment system, and other systems. The camera guided alignment system uses a camera to determine the position and alignment of the socket, and guides the test probe head into accurate insertion in the socket. This kind of system is complicated and expensive, and therefore a less complicated, simpler and more reliable and cheaper system is needed.
Accordingly, it is an object of the invention to provide a system for aligning a socket test probe for insertion into a socket which can be misaligned from its placement on a PCB.
It is a further object of the invention that such a test probe apparatus be simple, and yet accommodate a variety of misalignments of socket positions from the intended position on the PCB.
A further object of this system is to provide a socket test probe alignment system which reduces wear on both the socket test probe and the socket, and results in an improved life span of both the socket test probe and the socket.
It is a further object of the invention to provide an alignment system for socket test probes which gives accurate tests of the sockets electrical connections and circuitry.
Additional objects, advantages and novel features of the invention will be set forth in part in the description as follows, and in part will become apparent to those skilled in the art upon examination of the following, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.